Aligned lbt gaps for single operator fbe nr-ss

ABSTRACT

Aligned listen before talk (LBT) gaps for single operator frame-based equipment (FBE) mode new radio (NR) shared spectrum (NR-SS) is disclosed. Within the FBE mode network, the base station determines a plurality of potential transmission bursts within a fixed frame period. The base station may then reserve a plurality of LBT gaps prior to the starting position of each such transmission burst. The base station communicates the location of each of the LBT gaps to all neighboring network entities and contends for access to the fixed frame period at the beginning of the frame regardless of whether it has data for transmission during the frame. Each neighboring base station that receives the LBT gaps locations will use the same locations in order to align the LBT gaps over the FBE mode network.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/664,599, entitled, “ALIGNED LBT GAPS FOR SINGLEOPERATOR FBE NR-SS,” filed on Apr. 30, 2018, which is expresslyincorporated by reference herein in its entirety.

BACKGROUND Field

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to aligned listen beforetalk (LBT) gaps for single operator frame based equipment (FBE) newradio (NR) shared spectrum (NR-SS) networks.

Background

Wireless communication networks are widely deployed to provide variouscommunication services such as voice, video, packet data, messaging,broadcast, and the like. These wireless networks may be multiple-accessnetworks capable of supporting multiple users by sharing the availablenetwork resources. Such networks, which are usually multiple accessnetworks, support communications for multiple users by sharing theavailable network resources. One example of such a network is theUniversal Terrestrial Radio Access Network (UTRAN). The UTRAN is theradio access network (RAN) defined as a part of the Universal MobileTelecommunications System (UMTS), a third generation (3G) mobile phonetechnology supported by the 3rd Generation Partnership Project (3GPP).Examples of multiple-access network formats include Code DivisionMultiple Access (CDMA) networks, Time Division Multiple Access (TDMA)networks, Frequency Division Multiple Access (FDMA) networks, OrthogonalFDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.

A wireless communication network may include a number of base stationsor node Bs that can support communication for a number of userequipments (UEs). A UE may communicate with a base station via downlinkand uplink. The downlink (or forward link) refers to the communicationlink from the base station to the UE, and the uplink (or reverse link)refers to the communication link from the UE to the base station.

A base station may transmit data and control information on the downlinkto a UE and/or may receive data and control information on the uplinkfrom the UE. On the downlink, a transmission from the base station mayencounter interference due to transmissions from neighbor base stationsor from other wireless radio frequency (RF) transmitters. On the uplink,a transmission from the UE may encounter interference from uplinktransmissions of other UEs communicating with the neighbor base stationsor from other wireless RF transmitters. This interference may degradeperformance on both the downlink and uplink.

As the demand for mobile broadband access continues to increase, thepossibilities of interference and congested networks grows with more UEsaccessing the long-range wireless communication networks and moreshort-range wireless systems being deployed in communities. Research anddevelopment continue to advance wireless technologies not only to meetthe growing demand for mobile broadband access, but to advance andenhance the user experience with mobile communications.

SUMMARY

In one aspect of the disclosure, a method of wireless communicationincludes determining, by a base station, a plurality of potentialtransmission bursts within a fixed frame period in a frame-basedequipment (FBE) mode network, reserving, by the base station, aplurality of listen before talk (LBT) gaps before a starting position ofeach burst of the plurality of potential transmission bursts,communicating, by the base station, a location of the plurality of LBTgaps to one or more network entities connected for communication on theFBE mode network, and contending, by the base station, for access to thefixed frame period at a beginning of the fixed frame period.

In an additional aspect of the disclosure, a method of wirelesscommunication includes receiving, by a UE from a serving base station, alocation of a plurality of LBT gaps within a fixed frame period on a FBEmode network, refraining, by the UE, from transmissions during thelocation of the plurality of LBT gaps, and detecting, by the UE, acommon control signal from the serving base station at a beginning ofthe fixed frame period, wherein the common control signal identifies thefixed frame period is available for transmission according to anuplink-downlink configuration.

In an additional aspect of the disclosure, an apparatus configured forwireless communication is disclosed. The apparatus includes means fordetermining, by a base station, a plurality of potential transmissionbursts within a fixed frame period in a FBE mode network, means forreserving, by the base station, a plurality of LBT gaps before astarting position of each burst of the plurality of potentialtransmission bursts, means for communicating, by the base station, alocation of the plurality of LBT gaps to one or more network entitiesconnected for communication on the FBE mode network, and means forcontending, by the base station, for access to the fixed frame period ata beginning of the fixed frame period.

In an additional aspect of the disclosure, an apparatus configured forwireless communication is disclosed. The apparatus includes means forreceiving, by a UE from a serving base station, a location of aplurality of LBT gaps within a fixed frame period on a FBE mode network,means for refraining, by the UE, from transmissions during the locationof the plurality of LBT gaps, and means for detecting, by the UE, acommon control signal from the serving base station at a beginning ofthe fixed frame period, wherein the common control signal identifies thefixed frame period is available for transmission according to anuplink-downlink configuration.

In an additional aspect of the disclosure, a non-transitorycomputer-readable medium having program code recorded thereon. Theprogram code further includes program code executable by a computer forcausing the computer to determine, by a base station, a plurality ofpotential transmission bursts within a fixed frame period in a FBE modenetwork, program code executable by the computer for causing thecomputer to reserve, by the base station, a plurality of LBT gaps beforea starting position of each burst of the plurality of potentialtransmission bursts, program code executable by the computer for causingthe computer to communicate, by the base station, a location of theplurality of LBT gaps to one or more network entities connected forcommunication on the FBE mode network, and program code executable bythe computer for causing the computer to contend, by the base station,for access to the fixed frame period at a beginning of the fixed frameperiod.

In an additional aspect of the disclosure, the non-transitorycomputer-readable medium of wireless communication is disclosed. Theprogram code includes program code executable by the computer forcausing the computer to receive, by a UE from a serving base station, alocation of a plurality of LBT gaps within a fixed frame period on a FBEmode network, program code executable by the computer for causing thecomputer to refrain, by the UE, from transmissions during the locationof the plurality of LBT gaps, and program code executable by thecomputer for causing the computer to detect, by the UE, a common controlsignal from the serving base station at a beginning of the fixed frameperiod, wherein the common control signal identifies the fixed frameperiod is available for transmission according to an uplink-downlinkconfiguration.

In an additional aspect of the disclosure, an apparatus configured forwireless communication is disclosed. The apparatus includes at least oneprocessor; and a memory coupled to the at least one processor. Theprocessor is configured to determine, by a base station, a plurality ofpotential transmission bursts within a fixed frame period in a FBE modenetwork, to reserve, by the base station, a plurality of LBT gaps beforea starting position of each burst of the plurality of potentialtransmission bursts, to communicate, by the base station, a location ofthe plurality of LBT gaps to one or more network entities connected forcommunication on the FBE mode network, and to contend, by the basestation, for access to the fixed frame period at a beginning of thefixed frame period.

In an additional aspect of the disclosure, an apparatus configured forwireless communication is disclosed. The apparatus includes at least oneprocessor, and a memory coupled to the at least one processor. Theprocessor is configured to receive, by a UE from a serving base station,a location of a plurality of LBT gaps within a fixed frame period on aFBE mode network, to refrain, by the UE, from transmissions during thelocation of the plurality of LBT gaps, and to detect, by the UE, acommon control signal from the serving base station at a beginning ofthe fixed frame period, wherein the common control signal identifies thefixed frame period is available for transmission according to anuplink-downlink configuration.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description, and not as a definition of the limits ofthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presentdisclosure may be realized by reference to the following drawings. Inthe appended figures, similar components or features may have the samereference label. Further, various components of the same type may bedistinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

FIG. 1 is a block diagram illustrating details of a wirelesscommunication system.

FIG. 2 is a block diagram illustrating a design of a base station and aUE configured according to one aspect of the present disclosure.

FIG. 3 is a block diagram illustrating a wireless communication systemincluding base stations that use directional wireless beams.

FIGS. 4A and 4B are block diagrams illustrating example blocks executedto implement one aspect of the present disclosure.

FIG. 5 is a block diagram illustrating a base station and UE configuredaccording to one aspect of the present disclosure.

FIG. 6 is a block diagram illustrating a base station and UE operatingin FBE mode.

FIG. 7 is a block diagram illustrating base stations in communicationwith UEs, each of which is configured according to one aspect of thepresent disclosure.

FIG. 8 is a block diagram illustrating base stations and UEs configuredaccording to one aspect of the present disclosure.

FIG. 9 is a block diagram illustrating base station configured accordingto one aspect of the present disclosure.

FIG. 10 is a block diagram illustrating UE 115 configured according toone aspect of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to limit the scope of the disclosure.Rather, the detailed description includes specific details for thepurpose of providing a thorough understanding of the inventive subjectmatter. It will be apparent to those skilled in the art that thesespecific details are not required in every case and that, in someinstances, well-known structures and components are shown in blockdiagram form for clarity of presentation.

This disclosure relates generally to providing or participating inauthorized shared access between two or more wireless communicationssystems, also referred to as wireless communications networks. Invarious embodiments, the techniques and apparatus may be used forwireless communication networks such as code division multiple access(CDMA) networks, time division multiple access (TDMA) networks,frequency division multiple access (FDMA) networks, orthogonal FDMA(OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks,GSM networks, 5^(th) Generation (5G) or new radio (NR) networks, as wellas other communications networks. As described herein, the terms“networks” and “systems” may be used interchangeably.

An OFDMA network may implement a radio technology such as evolved UTRA(E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and thelike. UTRA, E-UTRA, and Global System for Mobile Communications (GSM)are part of universal mobile telecommunication system (UMTS). Inparticular, long term evolution (LTE) is a release of UMTS that usesE-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documentsprovided from an organization named “3rd Generation Partnership Project”(3GPP), and cdma2000 is described in documents from an organizationnamed “3rd Generation Partnership Project 2” (3GPP2). These variousradio technologies and standards are known or are being developed. Forexample, the 3rd Generation Partnership Project (3GPP) is acollaboration between groups of telecommunications associations thataims to define a globally applicable third generation (3G) mobile phonespecification. 3GPP long term evolution (LTE) is a 3GPP project whichwas aimed at improving the universal mobile telecommunications system(UMTS) mobile phone standard. The 3GPP may define specifications for thenext generation of mobile networks, mobile systems, and mobile devices.The present disclosure is concerned with the evolution of wirelesstechnologies from LTE, 4G, 5G, NR, and beyond with shared access towireless spectrum between networks using a collection of new anddifferent radio access technologies or radio air interfaces.

In particular, 5G networks contemplate diverse deployments, diversespectrum, and diverse services and devices that may be implemented usingan OFDM-based unified, air interface. In order to achieve these goals,further enhancements to LTE and LTE-A are considered in addition todevelopment of the new radio technology for 5G NR networks. The 5G NRwill be capable of scaling to provide coverage (1) to a massive Internetof things (IoTs) with an ultra-high density (e.g., ˜1 M nodes/km²),ultra-low complexity (e.g., ˜10 s of bits/sec), ultra-low energy (e.g.,˜10+ years of battery life), and deep coverage with the capability toreach challenging locations; (2) including mission-critical control withstrong security to safeguard sensitive personal, financial, orclassified information, ultra-high reliability (e.g., ˜99.9999%reliability), ultra-low latency (e.g., ˜1 ms), and users with wideranges of mobility or lack thereof; and (3) with enhanced mobilebroadband including extreme high capacity (e.g., ˜10 Tbps/km²), extremedata rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates),and deep awareness with advanced discovery and optimizations.

The 5G NR may be implemented to use optimized OFDM-based waveforms withscalable numerology and transmission time interval (TTI); having acommon, flexible framework to efficiently multiplex services andfeatures with a dynamic, low-latency time division duplex(TDD)/frequency division duplex (FDD) design; and with advanced wirelesstechnologies, such as massive multiple input, multiple output (MIMO),robust millimeter wave (mmWave) transmissions, advanced channel coding,and device-centric mobility. Scalability of the numerology in 5G NR,with scaling of subcarrier spacing, may efficiently address operatingdiverse services across diverse spectrum and diverse deployments. Forexample, in various outdoor and macro coverage deployments of less than3 GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz,for example over 1, 5, 10, 20 MHz, and the like bandwidth. For othervarious outdoor and small cell coverage deployments of TDD greater than3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHzbandwidth. For other various indoor wideband implementations, using aTDD over the unlicensed portion of the 5 GHz band, the subcarrierspacing may occur with 60 kHz over a 160 MHz bandwidth. Finally, forvarious deployments transmitting with mmWave components at a TDD of 28GHz, subcarrier spacing may occur with 120 kHz over a 500 MHz bandwidth.

The scalable numerology of the 5G NR facilitates scalable TTI fordiverse latency and quality of service (QoS) requirements. For example,shorter TTI may be used for low latency and high reliability, whilelonger TTI may be used for higher spectral efficiency. The efficientmultiplexing of long and short TTIs to allow transmissions to start onsymbol boundaries. 5G NR also contemplates a self-contained integratedsubframe design with uplink/downlink scheduling information, data, andacknowledgement in the same subframe. The self-contained integratedsubframe supports communications in unlicensed or contention-basedshared spectrum, adaptive uplink/downlink that may be flexiblyconfigured on a per-cell basis to dynamically switch between uplink anddownlink to meet the current traffic needs.

Various other aspects and features of the disclosure are furtherdescribed below. It should be apparent that the teachings herein may beembodied in a wide variety of forms and that any specific structure,function, or both being disclosed herein is merely representative andnot limiting. Based on the teachings herein one of an ordinary level ofskill in the art should appreciate that an aspect disclosed herein maybe implemented independently of any other aspects and that two or moreof these aspects may be combined in various ways. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, such an apparatusmay be implemented or such a method may be practiced using otherstructure, functionality, or structure and functionality in addition toor other than one or more of the aspects set forth herein. For example,a method may be implemented as part of a system, device, apparatus,and/or as instructions stored on a computer readable medium forexecution on a processor or computer. Furthermore, an aspect maycomprise at least one element of a claim.

FIG. 1 is a block diagram illustrating 5G network 100 including variousbase stations and UEs configured according to aspects of the presentdisclosure. The 5G network 100 includes a number of base stations 105and other network entities. A base station may be a station thatcommunicates with the UEs and may also be referred to as an evolved nodeB (eNB), a next generation eNB (gNB), an access point, and the like.Each base station 105 may provide communication coverage for aparticular geographic area. In 3GPP, the term “cell” can refer to thisparticular geographic coverage area of a base station and/or a basestation subsystem serving the coverage area, depending on the context inwhich the term is used.

A base station may provide communication coverage for a macro cell or asmall cell, such as a pico cell or a femto cell, and/or other types ofcell. A macro cell generally covers a relatively large geographic area(e.g., several kilometers in radius) and may allow unrestricted accessby UEs with service subscriptions with the network provider. A smallcell, such as a pico cell, would generally cover a relatively smallergeographic area and may allow unrestricted access by UEs with servicesubscriptions with the network provider. A small cell, such as a femtocell, would also generally cover a relatively small geographic area(e.g., a home) and, in addition to unrestricted access, may also providerestricted access by UEs having an association with the femto cell(e.g., UEs in a closed subscriber group (CSG), UEs for users in thehome, and the like). A base station for a macro cell may be referred toas a macro base station. A base station for a small cell may be referredto as a small cell base station, a pico base station, a femto basestation or a home base station. In the example shown in FIG. 1, the basestations 105 d and 105 e are regular macro base stations, while basestations 105 a-105 c are macro base stations enabled with one of 3dimension (3D), full dimension (FD), or massive MIMO. Base stations 105a-105 c take advantage of their higher dimension MIMO capabilities toexploit 3D beamforming in both elevation and azimuth beamforming toincrease coverage and capacity. Base station 105 f is a small cell basestation which may be a home node or portable access point. A basestation may support one or multiple (e.g., two, three, four, and thelike) cells.

The 5G network 100 may support synchronous or asynchronous operation.For synchronous operation, the base stations may have similar frametiming, and transmissions from different base stations may beapproximately aligned in time. For asynchronous operation, the basestations may have different frame timing, and transmissions fromdifferent base stations may not be aligned in time.

The UEs 115 are dispersed throughout the wireless network 100, and eachUE may be stationary or mobile. A UE may also be referred to as aterminal, a mobile station, a subscriber unit, a station, or the like. AUE may be a cellular phone, a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, atablet computer, a laptop computer, a cordless phone, a wireless localloop (WLL) station, or the like. In one aspect, a UE may be a devicethat includes a Universal Integrated Circuit Card (UICC). In anotheraspect, a UE may be a device that does not include a UICC. In someaspects, UEs that do not include UICCs may also be referred to asinternet of everything (loE) devices. UEs 115 a-115 d are examples ofmobile smart phone-type devices accessing 5G network 100 A UE may alsobe a machine specifically configured for connected communication,including machine type communication (MTC), enhanced MTC (eMTC),narrowband IoT (NB-IoT) and the like. UEs 115 e-115 k are examples ofvarious machines configured for communication that access 5G network100. A UE may be able to communicate with any type of the base stations,whether macro base station, small cell, or the like. In FIG. 1, alightning bolt (e.g., communication links) indicates wirelesstransmissions between a UE and a serving base station, which is a basestation designated to serve the UE on the downlink and/or uplink, ordesired transmission between base stations, and backhaul transmissionsbetween base stations.

In operation at 5G network 100, base stations 105 a-105 c serve UEs 115a and 115 b using 3D beamforming and coordinated spatial techniques,such as coordinated multipoint (CoMP) or multi-connectivity. Macro basestation 105 d performs backhaul communications with base stations 105a-105 c, as well as small cell, base station 105 f. Macro base station105 d also transmits multicast services which are subscribed to andreceived by UEs 115 c and 115 d. Such multicast services may includemobile television or stream video, or may include other services forproviding community information, such as weather emergencies or alerts,such as Amber alerts or gray alerts.

5G network 100 also support mission critical communications withultra-reliable and redundant links for mission critical devices, such UE115 e, which is a drone. Redundant communication links with UE 115 einclude from macro base stations 105 d and 105 e, as well as small cellbase station 105 f. Other machine type devices, such as UE 115 f(thermometer), UE 115 g (smart meter), and UE 115 h (wearable device)may communicate through 5G network 100 either directly with basestations, such as small cell base station 105 f, and macro base station105 e, or in multi-hop configurations by communicating with another userdevice which relays its information to the network, such as UE 115 fcommunicating temperature measurement information to the smart meter, UE115 g, which is then reported to the network through small cell basestation 105 f. 5G network 100 may also provide additional networkefficiency through dynamic, low-latency TDD/FDD communications, such asin a vehicle-to-vehicle (V2V) mesh network between UEs 115 i-115 kcommunicating with macro base station 105 e.

FIG. 2 shows a block diagram of a design of a base station 105 and a UE115, which may be one of the base station and one of the UEs in FIG. 1.At the base station 105, a transmit processor 220 may receive data froma data source 212 and control information from a controller/processor240. The control information may be for the PBCH, PCFICH, PHICH, PDCCH,EPDCCH, MPDCCH etc. The data may be for the PDSCH, etc. The transmitprocessor 220 may process (e.g., encode and symbol map) the data andcontrol information to obtain data symbols and control symbols,respectively. The transmit processor 220 may also generate referencesymbols, e.g., for the PSS, SSS, and cell-specific reference signal. Atransmit (TX) multiple-input multiple-output (MIMO) processor 230 mayperform spatial processing (e.g., precoding) on the data symbols, thecontrol symbols, and/or the reference symbols, if applicable, and mayprovide output symbol streams to the modulators (MODs) 232 a through 232t. Each modulator 232 may process a respective output symbol stream(e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator232 may further process (e.g., convert to analog, amplify, filter, andupconvert) the output sample stream to obtain a downlink signal.Downlink signals from modulators 232 a through 232 t may be transmittedvia the antennas 234 a through 234 t, respectively.

At the UE 115, the antennas 252 a through 252 r may receive the downlinksignals from the base station 105 and may provide received signals tothe demodulators (DEMODs) 254 a through 254 r, respectively. Eachdemodulator 254 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 254 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 256 may obtainreceived symbols from all the demodulators 254 a through 254 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 258 may process (e.g., demodulate,deinterleave, and decode) the detected symbols, provide decoded data forthe UE 115 to a data sink 260, and provide decoded control informationto a controller/processor 280.

On the uplink, at the UE 115, a transmit processor 264 may receive andprocess data (e.g., for the PUSCH) from a data source 262 and controlinformation (e.g., for the PUCCH) from the controller/processor 280. Thetransmit processor 264 may also generate reference symbols for areference signal. The symbols from the transmit processor 264 may beprecoded by a TX MIMO processor 266 if applicable, further processed bythe modulators 254 a through 254 r (e.g., for SC-FDM, etc.), andtransmitted to the base station 105. At the base station 105, the uplinksignals from the UE 115 may be received by the antennas 234, processedby the demodulators 232, detected by a MIMO detector 236 if applicable,and further processed by a receive processor 238 to obtain decoded dataand control information sent by the UE 115. The processor 238 mayprovide the decoded data to a data sink 239 and the decoded controlinformation to the controller/processor 240.

The controllers/processors 240 and 280 may direct the operation at thebase station 105 and the UE 115, respectively. The controller/processor240 and/or other processors and modules at the base station 105 mayperform or direct the execution of various processes for the techniquesdescribed herein. The controllers/processor 280 and/or other processorsand modules at the UE 115 may also perform or direct the execution ofthe functional blocks illustrated in FIGS. 4A and 4B, and/or otherprocesses for the techniques described herein. The memories 242 and 282may store data and program codes for the base station 105 and the UE115, respectively. A scheduler 244 may schedule UEs for datatransmission on the downlink and/or uplink.

Wireless communications systems operated by different network operatingentities (e.g., network operators) may share spectrum. In someinstances, a network operating entity may be configured to use anentirety of a designated shared spectrum for at least a period of timebefore another network operating entity uses the entirety of thedesignated shared spectrum for a different period of time. Thus, inorder to allow network operating entities use of the full designatedshared spectrum, and in order to mitigate interfering communicationsbetween the different network operating entities, certain resources(e.g., time) may be partitioned and allocated to the different networkoperating entities for certain types of communication.

For example, a network operating entity may be allocated certain timeresources reserved for exclusive communication by the network operatingentity using the entirety of the shared spectrum. The network operatingentity may also be allocated other time resources where the entity isgiven priority over other network operating entities to communicateusing the shared spectrum. These time resources, prioritized for use bythe network operating entity, may be utilized by other network operatingentities on an opportunistic basis if the prioritized network operatingentity does not utilize the resources. Additional time resources may beallocated for any network operator to use on an opportunistic basis.

Access to the shared spectrum and the arbitration of time resourcesamong different network operating entities may be centrally controlledby a separate entity, autonomously determined by a predefinedarbitration scheme, or dynamically determined based on interactionsbetween wireless nodes of the network operators.

In some cases, UE 115 and base station 105 may operate in a shared radiofrequency spectrum band, which may include licensed or unlicensed (e.g.,contention-based) frequency spectrum. In an unlicensed frequency portionof the shared radio frequency spectrum band, UEs 115 or base stations105 may traditionally perform a medium-sensing procedure to contend foraccess to the frequency spectrum. For example, UE 115 or base station105 may perform a listen before talk (LBT) procedure such as a clearchannel assessment (CCA) prior to communicating in order to determinewhether the shared channel is available. A CCA may include an energydetection procedure to determine whether there are any other activetransmissions. For example, a device may infer that a change in areceived signal strength indicator (RSSI) of a power meter indicatesthat a channel is occupied. Specifically, signal power that isconcentrated in a certain bandwidth and exceeds a predetermined noisefloor may indicate another wireless transmitter. A CCA also may includedetection of specific sequences that indicate use of the channel. Forexample, another device may transmit a specific preamble prior totransmitting a data sequence. In some cases, an LBT procedure mayinclude a wireless node adjusting its own backoff window based on theamount of energy detected on a channel and/or theacknowledge/negative-acknowledge (ACK/NACK) feedback for its owntransmitted packets as a proxy for collisions.

Use of a medium-sensing procedure to contend for access to an unlicensedshared spectrum may result in communication inefficiencies. This may beparticularly evident when multiple network operating entities (e.g.,network operators) are attempting to access a shared resource. In 5Gnetwork 100, base stations 105 and UEs 115 may be operated by the sameor different network operating entities. In some examples, an individualbase station 105 or UE 115 may be operated by more than one networkoperating entity. In other examples, each base station 105 and UE 115may be operated by a single network operating entity. Requiring eachbase station 105 and UE 115 of different network operating entities tocontend for shared resources may result in increased signaling overheadand communication latency.

FIG. 3 illustrates an example of a timing diagram 300 for coordinatedresource partitioning. The timing diagram 300 includes a superframe 305,which may represent a fixed duration of time (e.g., 20 ms). Superframe305 may be repeated for a given communication session and may be used bya wireless system such as 5G network 100 described with reference toFIG. 1. The superframe 305 may be divided into intervals such as anacquisition interval (A-INT) 310 and an arbitration interval 315. Asdescribed in more detail below, the A-INT 310 and arbitration interval315 may be subdivided into sub-intervals, designated for certainresource types, and allocated to different network operating entities tofacilitate coordinated communications between the different networkoperating entities. For example, the arbitration interval 315 may bedivided into a plurality of sub-intervals 320. Also, the superframe 305may be further divided into a plurality of subframes 325 with a fixedduration (e.g., 1 ms). While timing diagram 300 illustrates threedifferent network operating entities (e.g., Operator A, Operator B,Operator C), the number of network operating entities using thesuperframe 305 for coordinated communications may be greater than orfewer than the number illustrated in timing diagram 300.

The A-INT 310 may be a dedicated interval of the superframe 305 that isreserved for exclusive communications by the network operating entities.In some examples, each network operating entity may be allocated certainresources within the A-INT 310 for exclusive communications. Forexample, resources 330-a may be reserved for exclusive communications byOperator A, such as through base station 105 a, resources 330-b may bereserved for exclusive communications by Operator B, such as throughbase station 105 b, and resources 330-c may be reserved for exclusivecommunications by Operator C, such as through base station 105 c. Sincethe resources 330-a are reserved for exclusive communications byOperator A, neither Operator B nor Operator C can communicate duringresources 330-a, even if Operator A chooses not to communicate duringthose resources. That is, access to exclusive resources is limited tothe designated network operator. Similar restrictions apply to resources330-b for Operator B and resources 330-c for Operator C. The wirelessnodes of Operator A (e.g, UEs 115 or base stations 105) may communicateany information desired during their exclusive resources 330-a, such ascontrol information or data.

When communicating over an exclusive resource, a network operatingentity does not need to perform any medium sensing procedures (e.g.,listen-before-talk (LBT) or clear channel assessment (CCA)) because thenetwork operating entity knows that the resources are reserved. Becauseonly the designated network operating entity may communicate overexclusive resources, there may be a reduced likelihood of interferingcommunications as compared to relying on medium sensing techniques alone(e.g., no hidden node problem). In some examples, the A-INT 310 is usedto transmit control information, such as synchronization signals (e.g.,SYNC signals), system information (e.g., system information blocks(SIBs)), paging information (e.g., physical broadcast channel (PBCH)messages), or random access information (e.g., random access channel(RACH) signals). In some examples, all of the wireless nodes associatedwith a network operating entity may transmit at the same time duringtheir exclusive resources.

In some examples, resources may be classified as prioritized for certainnetwork operating entities. Resources that are assigned with priorityfor a certain network operating entity may be referred to as aguaranteed interval (G-INT) for that network operating entity. Theinterval of resources used by the network operating entity during theG-INT may be referred to as a prioritized sub-interval. For example,resources 335-a may be prioritized for use by Operator A and maytherefore be referred to as a G-INT for Operator A (e.g., G-INT-OpA).Similarly, resources 335-b may be prioritized for Operator B, resources335-c may be prioritized for Operator C, resources 335-d may beprioritized for Operator A, resources 335-e may be prioritized forOperator B, and resources 335-f may be prioritized for operator C.

The various G-INT resources illustrated in FIG. 3 appear to be staggeredto illustrate their association with their respective network operatingentities, but these resources may all be on the same frequencybandwidth. Thus, if viewed along a time-frequency grid, the G-INTresources may appear as a contiguous line within the superframe 305.This partitioning of data may be an example of time divisionmultiplexing (TDM). Also, when resources appear in the same sub-interval(e.g., resources 340-a and resources 335-b), these resources representthe same time resources with respect to the superframe 305 (e.g., theresources occupy the same sub-interval 320), but the resources areseparately designated to illustrate that the same time resources can beclassified differently for different operators.

When resources are assigned with priority for a certain networkoperating entity (e.g., a G-INT), that network operating entity maycommunicate using those resources without having to wait or perform anymedium sensing procedures (e.g., LBT or CCA). For example, the wirelessnodes of Operator A are free to communicate any data or controlinformation during resources 335-a without interference from thewireless nodes of Operator B or Operator C.

A network operating entity may additionally signal to another operatorthat it intends to use a particular G-INT. For example, referring toresources 335-a, Operator A may signal to Operator B and Operator C thatit intends to use resources 335-a. Such signaling may be referred to asan activity indication. Moreover, since Operator A has priority overresources 335-a, Operator A may be considered as a higher priorityoperator than both Operator B and Operator C. However, as discussedabove, Operator A does not have to send signaling to the other networkoperating entities to ensure interference-free transmission duringresources 335-a because the resources 335-a are assigned with priorityto Operator A.

Similarly, a network operating entity may signal to another networkoperating entity that it intends not to use a particular G-INT. Thissignaling may also be referred to as an activity indication. Forexample, referring to resources 335-b, Operator B may signal to OperatorA and Operator C that it intends not to use the resources 335-b forcommunication, even though the resources are assigned with priority toOperator B. With reference to resources 335-b, Operator B may beconsidered a higher priority network operating entity than Operator Aand Operator C. In such cases, Operators A and C may attempt to useresources of sub-interval 320 on an opportunistic basis. Thus, from theperspective of Operator A, the sub-interval 320 that contains resources335-b may be considered an opportunistic interval (O-INT) for Operator A(e.g., O-INT-OpA). For illustrative purposes, resources 340-a mayrepresent the O-INT for Operator A. Also, from the perspective ofOperator C, the same sub-interval 320 may represent an O-INT forOperator C with corresponding resources 340-b. Resources 340-a, 335-b,and 340-b all represent the same time resources (e.g., a particularsub-interval 320), but are identified separately to signify that thesame resources may be considered as a G-INT for some network operatingentities and yet as an O-INT for others.

To utilize resources on an opportunistic basis, Operator A and OperatorC may perform medium-sensing procedures to check for communications on aparticular channel before transmitting data. For example, if Operator Bdecides not to use resources 335-b (e.g., G-INT-OpB), then Operator Amay use those same resources (e.g., represented by resources 340-a) byfirst checking the channel for interference (e.g., LBT) and thentransmitting data if the channel was determined to be clear. Similarly,if Operator C wanted to access resources on an opportunistic basisduring sub-interval 320 (e.g., use an O-INT represented by resources340-b) in response to an indication that Operator B was not going to useits G-INT, Operator C may perform a medium sensing procedure and accessthe resources if available. In some cases, two operators (e.g., OperatorA and Operator C) may attempt to access the same resources, in whichcase the operators may employ contention-based procedures to avoidinterfering communications. The operators may also have sub-prioritiesassigned to them designed to determine which operator may gain access toresources if more than operator is attempting access simultaneously.

In some examples, a network operating entity may intend not to use aparticular G-INT assigned to it, but may not send out an activityindication that conveys the intent not to use the resources. In suchcases, for a particular sub-interval 320, lower priority operatingentities may be configured to monitor the channel to determine whether ahigher priority operating entity is using the resources. If a lowerpriority operating entity determines through LBT or similar method thata higher priority operating entity is not going to use its G-INTresources, then the lower priority operating entities may attempt toaccess the resources on an opportunistic basis as described above.

In some examples, access to a G-INT or O-INT may be preceded by areservation signal (e.g., request-to-send (RTS)/clear-to-send (CTS)),and the contention window (CW) may be randomly chosen between one andthe total number of operating entities.

In some examples, an operating entity may employ or be compatible withcoordinated multipoint (CoMP) communications. For example an operatingentity may employ CoMP and dynamic time division duplex (TDD) in a G-INTand opportunistic CoMP in an O-INT as needed.

In the example illustrated in FIG. 3, each sub-interval 320 includes aG-INT for one of Operator A, B, or C. However, in some cases, one ormore sub-intervals 320 may include resources that are neither reservedfor exclusive use nor reserved for prioritized use (e.g., unassignedresources). Such unassigned resources may be considered an O-INT for anynetwork operating entity, and may be accessed on an opportunistic basisas described above.

In some examples, each subframe 325 may contain 14 symbols (e.g., 250-μsfor 60 kHz tone spacing). These subframes 325 may be standalone,self-contained Interval-Cs (ITCs) or the subframes 325 may be a part ofa long ITC. An ITC may be a self-contained transmission starting with adownlink transmission and ending with a uplink transmission. In someembodiments, an ITC may contain one or more subframes 325 operatingcontiguously upon medium occupation. In some cases, there may be amaximum of eight network operators in an A-INT 310 (e.g., with durationof 2 ms) assuming a 250-μs transmission opportunity.

Although three operators are illustrated in FIG. 3, it should beunderstood that fewer or more network operating entities may beconfigured to operate in a coordinated manner as described above. Insome cases, the location of the G-INT, O-INT, or A-INT within superframe305 for each operator is determined autonomously based on the number ofnetwork operating entities active in a system. For example, if there isonly one network operating entity, each sub-interval 320 may be occupiedby a G-INT for that single network operating entity, or thesub-intervals 320 may alternate between G-INTs for that networkoperating entity and O-INTs to allow other network operating entities toenter. If there are two network operating entities, the sub-intervals320 may alternate between G-INTs for the first network operating entityand G-INTs for the second network operating entity. If there are threenetwork operating entities, the G-INT and O-INTs for each networkoperating entity may be designed as illustrated in FIG. 3. If there arefour network operating entities, the first four sub-intervals 320 mayinclude consecutive G-INTs for the four network operating entities andthe remaining two sub-intervals 320 may contain O-INTs. Similarly, ifthere are five network operating entities, the first five sub-intervals320 may contain consecutive G-INTs for the five network operatingentities and the remaining sub-interval 320 may contain an O-INT. Ifthere are six network operating entities, all six sub-intervals 320 mayinclude consecutive G-INTs for each network operating entity. It shouldbe understood that these examples are for illustrative purposes only andthat other autonomously determined interval allocations may be used.

It should be understood that the coordination framework described withreference to FIG. 3 is for illustration purposes only. For example, theduration of superframe 305 may be more or less than 20 ms. Also, thenumber, duration, and location of sub-intervals 320 and subframes 325may differ from the configuration illustrated. Also, the types ofresource designations (e.g., exclusive, prioritized, unassigned) maydiffer or include more or less sub-designations.

Different regions may have different regulatory requirements forcommunication operations over an unlicensed band. Some regulations maymandate the equipment operating on unlicensed spectrum to implement anLBT procedure, such as by performing a clear channel assessment (CCA),before starting a transmission to verify that the operating channel isnot occupied. On the unlicensed 5 GHz band, two of modes of operationhave been suggested: frame-based equipment (FBE), and load-basedequipment (LBE).

FBE is the equipment in which the transmit/receive structure may not bedirectly demand-driven, but, instead, operates according to fixedtiming. LBT/CCA may therefore be performed periodically at predefinedtime instances according to a predetermined frame structure, such as:

Fixed-Frame Period=channel occupancy time (CoT)+idle period  (1)

Where the fixed frame period (e.g., 1-10 ms) represents the periodicityover which the LBT/CCA may be performed, the CoT represents the totaltime during which equipment has transmissions during the fixed-frameperiod on a given channel without re-evaluating the availability of thatchannel, and the idle period represents the total time within thefixed-frame period, during which the equipment has no transmissions.Some regulations provide that the idle period should be at least 5% ofthe channel occupancy time in any given fixed-frame period. If theequipment finds the operating channel(s) to be clear, it may thentransmit immediately. Otherwise, if the equipment finds the operatingchannel occupied, it would not transmit on that channel during theremainder of the current fixed-frame period.

Unlike for FBE, load-based equipment is not restricted to performLBT/CCA according to a fixed frame structure. Instead, LBE may performLBT/CCA on an ad hoc basis, whenever it has data to transmit. Before atransmission on an operating channel, an LBE would perform a CCA todetect the energy on the channel. If the equipment finds the operatingchannel(s) to be clear, it may transmit immediately. The total time thatan LBE makes use of an operating channel is the maximum channeloccupancy time (MCOT). In one example implementation, MCOT may be lessthan (13/32)×q milliseconds, where q={4 . . . 32}. (E.g., when q=32, theMCOT=13 ms). Otherwise, if the equipment finds an operating channeloccupied, it will not immediately transmit on the channel, but willperform an Extended CCA (ECCA) at a later time during the MCOT. Forexample, the LBE would observe the operating channel for the duration ofa random factor N multiplied by the CCA observation time. N representsthe number of clear idle slots resulting in a total idle period that theLBE would observe before initiation of the transmission. The value of Nmay be randomly selected in the range 1 . . . q every time an ECCA is tobe performed. N may be stored in a counter which is decremented everytime a CCA slot is considered to be “unoccupied”. When the counterreaches zero, the LBT may transmit.

5G technologies include provision for an Internet of Things (IoT)functionality that allows structured communications over licensed andunlicensed spectrum by multiple dedicated UEs, which may be lower power,single purposes devices (measurement instruments, appliances, industrialequipment, and the like). When implemented for industrial IoT, there maybe a single operator environment, for which an FBE-mode of operation maybe beneficial.

In FBE-mode operations, if a base station does not contend for access atthe beginning of a frame, it may not be able to contend in the middle ofthe frame thereafter. Thus, without the ability to grab a communicationchannel in the middle of a designated frame, such FBE-mode operationscould not handle urgent traffic, such as ultra-reliable low latencycommunication (URLLC) traffic.

In addition, an opportunistic frequency switching has been proposed forFBE-mode operations, in which a base station may switch to anotherfrequency when the current frequency suffers from interference. If aserved UE does not decode any common signal from the base station, theUE will retune to another carrier frequency and monitor for commonsignaling on the other frequency. Additional UE complexity may becreated if a given base station does not send common signaling at thebeginning of a frame. Various aspects of the present disclosure aredirected providing aligned LBT gaps and having base stations contend forand transmit short downlink control signaling at the beginning of frame,even if there is no current traffic need. The base station may not knowthere will be arrival of traffic later on in the fixed-frame period.

FIG. 4A is a block diagram illustrating example blocks executed by abase station to implement one aspect of the present disclosure. Theexample blocks will also be described with respect to base station 105as illustrated in FIG. 9. FIG. 9 is a block diagram illustrating basestation 105 configured according to one aspect of the presentdisclosure. Base station 105 includes the structure, hardware, andcomponents as illustrated for base station 105 of FIG. 2. For example,base station 105 includes controller/processor 240, which operates toexecute logic or computer instructions stored in memory 242, as well ascontrolling the components of base station 105 that provide the featuresand functionality of base station 105. Base station 105, under controlof controller/processor 240, transmits and receives signals via wirelessradios 900 a-t and antennas 234 a-t. Wireless radios 900 a-t includesvarious components and hardware, as illustrated in FIG. 2 for basestation 105, including modulator/demodulators 232 a-t, MIMO detector236, receive processor 238, transmit processor 220, and TX MIMOprocessor 230.

At block 400, a base station determines a plurality of potentialtransmission bursts within a fixed frame period in an FBE mode network.Within the fixed frame period, there may be many opportunities fortransmission bursts, including both downlink and uplink transmissionbursts. The base station, such as base station 105, may determine anuplink-downlink configuration 901 for the potential transmission burststhat schedules transmission locations or slots within which atransmission burst may be made. Base station 105 stores the determineduplink-downlink configuration 901 in memory 242.

At block 401, the base station reserves a plurality of LBT gaps before astarting position of each burst of the plurality of potentialdownlink-uplink bursts. Before transmissions on the operating channel,each transmitting entity will perform an LBT procedures (e.g., a regularor abbreviated LBT). Base station 105, under control ofcontroller/processor 240, executes LBT gap scheduling logic 902, storedin memory 242. The execution environment of LBT gap scheduling logic 902allows for scheduler 244 to schedule the locations of the LBT gaps priorto each potential transmission burst location. After determining thepotential transmission bursts and uplink-downlink configuration, basestation 105, under control of controller/processor 240 and scheduler244, may reserve locations for LBT gaps before each potentialtransmission burst location.

At block 402, the base station communicates a location of the pluralityof LBT gaps to one or more network entities connected for communicationon the FBE mode network. As a part of the system information, basestation 105 would communicate the location of the LBT gaps anduplink-downlink configuration 901 via wireless radios 900 a-t andantennas 234 a-t. Communication of the gaps allows any transmittingentity knowledge of the gap in order to perform the LBT prior to itstransmission burst.

At block 403, the base station contends for access to the fixed frameperiod at a beginning of the fixed frame period. Base station 105, undercontrol of controller/processor 240 executes LBT logic 903, stored inmemory 242. The execution environment of LBT logic 903 provides forappropriate energy/preamble detection to be performed in order to detectwhether or not the channel is occupied. After performing a successfulLBT procedure during the idle period of the previous fixed frame period,base station 105 will contend for access at the beginning of the fixedframe period and transmit a common control signal indicating that thechannel is available for communication. Base station 105 contends foraccess regardless of whether it has data or knows of data to becommunicated later in the fixed frame period.

FIG. 4B is a block diagram illustrating example block executed by a UEto implement one aspect of the present disclosure. The example blockswill also be described with respect to UE 115 as illustrated in FIG. 10.FIG. 10 is a block diagram illustrating UE 115 configured according toone aspect of the present disclosure. UE 115 includes the structure,hardware, and components as illustrated for UE 115 of FIG. 2. Forexample, UE 115 includes controller/processor 280, which operates toexecute logic or computer instructions stored in memory 282, as well ascontrolling the components of UE 115 that provide the features andfunctionality of UE 115. UE 115, under control of controller/processor280, transmits and receives signals via wireless radios 1000 a-r andantennas 252 a-r. Wireless radios 1000 a-r includes various componentsand hardware, as illustrated in FIG. 2 for UE 115, includingmodulator/demodulators 254 a-r, MIMO detector 256, receive processor258, transmit processor 264, and TX MIMO processor 266.

At block 404, a UE receives a location of a plurality of LBT gaps withina fixed frame period on a FBE mode network. For a UE, such as UE 115,within the FBE-mode operation of the network, it will receive signalsvia antennas 252 a-r and wireless radios 1000 a-r that identify alocation of LBT gaps prior to each potential transmission burst locationin the fixed-frame period. UE 115 stores record of the gaps in memory282, at LBT gaps 1002. If UE 115 were scheduled for uplink transmissionduring one of the uplink portions or slots of the fixed-frame period asindicated by uplink-downlink configuration 1001, stored in memory 282,it would perform LBT during the gap prior to transmission. UE 115, undercontrol of controller/processor 282, would execute LBT logic 1004. Theexecution environment of LBT logic 1004 provides for UE 115 to performthe energy/preamble detection process, as described above, in order tocomplete an LBT procedure. The location of the LBT gaps may be receivedin a form of a map of locations or via a set of resources for ratematching around.

At block 405, the UE refrains from transmissions during the location ofthe plurality of LBT gaps. With the location of each LBT gap, in orderto preserve the gaps for LBT by transmitting entities, each networkentity would refrain from transmissions during the LBT gap identified bythe received location. UE 115, under control of controller/processor280, would refrain either by using a map of the gaps within which itwould not transmit or would identify resources around which it wouldrate match in LBT gaps 1002 and, thus, not transmit.

At block 406, the UE detects a common control signal from the servingbase station at a beginning of the fixed frame period, wherein thecommon control signal identifies the fixed frame period is available fortransmission according to an uplink-downlink configuration. UE 115,under control of controller/processor 280, executes FBE access logic1003, stored in memory 282. The execution environment of FBE accesslogic 1003 provides for UE 115 to listen, via antennas 252 a-r andwireless radios 1000 a-r, at the beginning of each fixed frame period todetect for the common signaling from the serving base station. If UE 115detects the common signaling, it is aware that communications may occurduring the fixed frame period. Otherwise, UE 115, under control ofcontroller/processor 280, would retune to a different frequency knownwithin the execution environment of FBE access logic 1003 as part of thenetwork. UE 115 would monitor again on the new frequency for the commonsignaling.

FIG. 5 is a block diagram illustrating a base station 105 and UE 115configured according to one aspect of the present disclosure. In theillustrated example, base station 105 and UE 115 are within a singleoperator environment operating in FBE mode. Within the idle period priorto fixed frame period 50, base station 105 performs LBT 500 to determinewhether or not the operating channel is occupied. After detectingsuccess of LBT 500, base station 105 contends for the operating channeland transmits a common control signal 501. Common control signal 501indicates that base station 105 has secured access to the operatingchannel and that the operating channel is available for communicationswith the served UEs, including UE 115. However, base station 105 doesnot have any data for downlink transmission to any of the served UEs,including UE 115. According to the present aspect, even though basestation 105 has no data for transmission, it would still perform LBT 500securing access to the operating channel and communications during fixedframe period 50.

Fixed frame period 50 includes CoT 502, which remains mostly emptybecause of the lace of data, and idle period 503. Base station 105 willperform LBT 504 during idle time 503 in order to detect channeloccupancy for fixed frame period 51. After CoT 502, base station 105obtains data scheduled for downlink to UE 115. Once success is detectedfor LBT 504, base station 105 contends for the operating channel againduring fixed frame period 51 and transmits common control and data 505.Common control and data 505 includes the common control signaling that,again, identifies to neighboring network entities that the operatingchannel is open for communication during fixed frame period 51. It alsoincludes the downlink data identified for UE 115. The empty portion ofCoT 506 is smaller in fixed frame period 51 than fixed frame period 50because of the data available for downlink transmission by base station105. After CoT 506, fixed frame period 51 ends with idle period 507.

It should be noted that, while not shown, base station 105 would againperform an LBT procedure during idle period 507 to contend for accessduring the next fixed frame period regardless of whether there is anydata at base station 105 or known to be received by base station 105 fordownlink transmissions to any of its served UEs, including UE 115.According to the various aspects of the present disclosure, base station105 would attempt access to the operating channel for each fixed frameperiod regardless of having any data for transmission.

FIG. 6 is a block diagram illustrating a base station 105 and UE 115operating in FBE mode. Within each fixed frame period of FBE operations,there may be multiple transmission burst occasions, including downlinkand uplink transmission bursts. In order to efficiently organize eachfixed frame period, such as fixed frame periods 60 and 61, base station105 may determine an uplink-downlink configuration, which sets differenttransmission units, portions, or slots of the fixed frame periodidentified for either uplink or downlink transmission bursts. Theuplink-downlink configuration may further be set by base station 105based on scheduled communications that are known. For example, in fixedframe period 60, base station 105 schedules uplink-downlinkconfiguration 601 within CoT 602, while it schedules uplink-downlinkconfiguration 605 within CoT 606 of fixed frame period 61. In order tomaintain access to the operating channel, base station 105 would performLBT 604 during idle period 603 of fixed frame period 60 to secure accessduring fixed frame period 61.

FIG. 7 is a block diagram illustrating base stations 105 f and 105 g incommunication with UEs 115 g and 115 f, respectively, each of which isconfigured according to one aspect of the present disclosure. Basestations 105 f and 105 g operate within the same industrial facility andare synchronized to each other, but each maintains its own communicationscheduling. Transmission stream 71 includes the transmissions betweenbase station 105 f and UE 115 g, while transmission stream 72 includesthe transmission between base station 105 g and UE 115 f. Theillustrated communications between the entities cover fixed frame period70 for both transmission streams 71 and 72. In FBE operations, eachnetwork entity that will transmit within any given fixed frame periodwould perform an LBT procedure (e.g., regular or one shot LBT) for eachtransmission burst in COT. With multiple uplink-downlink transmissionbursts within fixed frame period 70 over both transmission streams 71and 72, consideration should be made to avoid blocking, such as basestation to base station blocking, base station to UE blocking, or UE toUE blocking due to LBT. Thus, prior to each transmission burst, thetransmitting entity will perform an LBT. A gap for these LBT may beincluded in the scheduling and configuration of the frame.

In a multi-cell deployment, such as with base stations 105 f and 105 g,the different uplink-downlink configurations, each having reserved LBTgaps prior to the burst location may result in transmissions of one cellcolliding with transmissions of another. For example, uplink burst 704from UE 115 f collides at 700 with the attempted LBT of UE 115 g duringgap 705. Similarly, uplink burst 706 from UE 115 g would collide at 701with an LBT attempt by base station 105 g in gap 707. Downlink burst 708by base station 105 g would collide at 702 with an LBT attempt by basestation 105 f at gap 709, and downlink burst 710 by base station 105 fwould collide with an LBT attempt by UE 115 f at gap 711. Accordingly,without greater coordination between cells (base stations 105 g and 105g) colliding communications may cause low efficiency communications. UEto base station or base station to UE interference is also possible whenthe deployment is too dense (e.g., energy detection above a thresholddue to signals from a neighbor cell). For a dense factory deployment,base station to base station interference may also be problematic.

It should be noted that within a single cell deployment, the LBT gapscan be easily guaranteed. Between each downlink to uplink and uplink todownlink switching point, a gap is scheduled. For downlink to uplinktransitions, there may already be a gap scheduled in NR deployments. Foruplink to downlink transitions or TDM uplink transmissions, there may beno gap in NR deployments, but various aspects of the present disclosuremay provide for such gaps to be defined.

FIG. 8 is a block diagram illustrating base stations 105 and 105 g andUEs 115 and 115 f configured according to one aspect of the presentdisclosure. Base stations 105/105 g and UEs 115/115 f operated within anFBE-mode environment. In order to avoid colliding communications betweendifferent cells, when operating in such a multiple-cell environment,each LBT gap scheduled within a fixed frame period, such as fixed frameperiod 80, will be aligned across base stations 105 and 105 g. Asillustrated, based on the potential transmission bursts available infixed frame period 80, base station 105 defines an uplink-downlinkconfiguration in transmission stream 81 that identifies the startingpoints 801 of each transmission unit or slot (e.g., each uplink ordownlink occasion). LBT gaps 800 are also scheduled prior to therespective starting point 801. LBT gaps 800 are also scheduled acrosstransmission stream 82, between base station 105 g and UE 115 f. LBTgaps 800 are aligned between transmission streams 81 and 82. Thus,collisions of competing signals between the base station 105-UE 115 pairand base station 105 g-UE 115 f pair would be avoided.

In order to communicate the alignment of LBT gaps 800, base station 105may broadcast or transmit not only the uplink-downlink configuration forfixed frame period 80, but the locations of LBT gaps 800. Thisinformation may be received by both served UE 115 and neighbor UE 115 f,and neighbor base station 105 g. Therefore, all neighboring basestations, including base station 105 and 105 g, would follow the samepattern for LBT gaps 800 for RRC configured transmission and grants.That configuration of LBT gaps 800 may still change over time, but allbase stations within the area would change configurations at the sametime.

It should be noted that, in order to avoid cross link interference(e.g., UE 115 uplink transmission interfering with downlinktransmissions to UE 115 f), both base station 115 and 115 g may maintainthe same uplink-downlink configuration as well. The uplink-downlinkpattern can be regular or irregular, as selected by base station 115.

It should further be noted that no gap may be needed within one downlinkburst, while a gap may be needed between multiple TDM uplinktransmissions.

Communication of the location of LBT gaps 800 by base station 105 may bemade using system information broadcasts (e.g., MIB, SIBs, etc.) or maybe semi-statically transmitted using RRC communications or othertransmission grants. In such implementations, base station 105 wouldtransmit the direct location/scheduling of LBT gaps 800 within fixedframe period 80. In additional aspects of the present disclosure, thelocation of LBT gaps 800 may be implicitly communicated by base station105 via signaling of resources for rate matching. NR networks have bothsymbol-RB level rate matching and RE-level rate matching capabilities.Symbol-RB level rate matching of a resource set may be supported by abitmap (e.g., 2-bits, 3-bits, etc.). RE-level rate matching is currentlydefined for LTE CRS transmission. Both of these NR rate matchingfunctions are for PDSCH rate matching, and while uplink rate matching(e.g., PUSCH, etc.) is not covered, uplink rate matching may also beconsidered assuming the scheduler has sufficient capabilities.

In single operator FBE mode environment, the concept of aligned LBT gapsacross base stations is suggested in the various aspects of the presentdisclosure. As noted above, the scheduler may enforce LBT gaps 800 byincluding scheduling of the gaps in all RRC configurations andtransmission grants. Alternatively, various aspects of the presentdisclosure may provide for a symbol-level rate matching resource setthat is configured to the UE, such as to UE 115, and all otherconfigured or granted transmission/reception will rate match aroundthose symbols of the signaled resource set, in both downlink and uplinktransmission bursts. This applies to both DL and UL transmissions. Insuch an implementation, RRC signaling (e.g., cell-specific orUE-specific) or dynamic L1 signaling in DCI (downlink controlinformation) may be used by base station 105 to indicate the symbols torate match around within fixed frame period 80. Thus, each of served UE115 and neighboring network entities, base station 105 g and UE 115 fwould have the specific symbols around which to rate match in order toleave LBT gaps 800.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

The functional blocks and modules in FIGS. 4A and 4B may compriseprocessors, electronics devices, hardware devices, electronicscomponents, logical circuits, memories, software codes, firmware codes,etc., or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure. Skilled artisans will also readilyrecognize that the order or combination of components, methods, orinteractions that are described herein are merely examples and that thecomponents, methods, or interactions of the various aspects of thepresent disclosure may be combined or performed in ways other than thoseillustrated and described herein.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure herein may be embodied directly in hardware, in a softwaremodule executed by a processor, or in a combination of the two. Asoftware module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such that theprocessor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal. In the alternative, theprocessor and the storage medium may reside as discrete components in auser terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another.Computer-readable storage media may be any available media that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, such computer-readable media can compriseRAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic diskstorage or other magnetic storage devices, or any other medium that canbe used to carry or store desired program code means in the form ofinstructions or data structures and that can be accessed by ageneral-purpose or special-purpose computer, or a general-purpose orspecial-purpose processor. Also, a connection may be properly termed acomputer-readable medium. For example, if the software is transmittedfrom a website, server, or other remote source using a coaxial cable,fiber optic cable, twisted pair, or digital subscriber line (DSL), thenthe coaxial cable, fiber optic cable, twisted pair, or DSL, are includedin the definition of medium. Disk and disc, as used herein, includescompact disc (CD), laser disc, optical disc, digital versatile disc(DVD), floppy disk and blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media.

As used herein, including in the claims, the term “and/or,” when used ina list of two or more items, means that any one of the listed items canbe employed by itself, or any combination of two or more of the listeditems can be employed. For example, if a composition is described ascontaining components A, B, and/or C, the composition can contain Aalone; B alone; C alone; A and B in combination; A and C in combination;B and C in combination; or A, B, and C in combination. Also, as usedherein, including in the claims, “or” as used in a list of itemsprefaced by “at least one of” indicates a disjunctive list such that,for example, a list of “at least one of A, B, or C” means A or B or C orAB or AC or BC or ABC (i.e., A and B and C) or any of these in anycombination thereof.

The previous description of the disclosure is provided to enable anyperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Thus, the disclosure is not intended to be limited tothe examples and designs described herein but is to be accorded thewidest scope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method of wireless communication, comprising:determining, by a base station, a plurality of potential transmissionbursts within a fixed frame period in a frame-based equipment (FBE) modenetwork; reserving, by the base station, a plurality of listen beforetalk (LBT) gaps before a starting position of each burst of theplurality of potential transmission bursts; communicating, by the basestation, a location of the plurality of LBT gaps to one or more networkentities connected for communication on the FBE mode network; andcontending, by the base station, for access to the fixed frame period ata beginning of the fixed frame period.
 2. The method of claim 1, whereinthe contending for access to the fixed frame period includes: performingan LBT procedure; and transmitting at least a common downlink controlsignal, in response to success of the LBT procedure, wherein thedownlink control signal identifies to one or more served user equipments(UEs) that the fixed frame period is available for communication,wherein the contending is performed by the base station at every fixedframe period regardless of having data for transmission.
 3. The methodof claim 1, wherein the one or more network entities includes one ormore of: one or more served user equipments (UEs); and one or moreneighboring base stations.
 4. The method of claim 3, wherein thedetermining includes one of: obtaining a downlink-uplink configurationfor the fixed frame period from a central controller; negotiating thedownlink-uplink configuration with one or more additional base stations;or determining at least one of: uplink or downlink transmission schedulefor the fixed frame period.
 5. The method of claim 1, wherein thecommunicating the location includes one of: signaling a gap patternidentifying the location of the plurality of gaps in the fixed frameperiod; or identifying a set of transmission resources in the fixedframe period around which the one or more network entities are to ratematch around, wherein the set of transmission resources includes thelocation of the plurality of gaps.
 6. A method of wirelesscommunication, comprising: receiving, by a user equipment (UE) from aserving base station, a location of a plurality of LBT gaps within afixed frame period on a frame-based equipment (FBE) mode network;refraining, by the UE, from transmissions during the location of theplurality of LBT gaps; and detecting, by the UE, a common control signalfrom the serving base station at a beginning of the fixed frame period,wherein the common control signal identifies the fixed frame period isavailable for transmission according to an uplink-downlinkconfiguration.
 7. The method of claim 6, further including: identifying,by the UE, data for uplink transmission; performing, by the UE, a listenbefore talk (LBT) procedure at a gap of the plurality of LBT gapsassociated with an uplink transmission segment of the uplink-downlinkconfiguration; and transmitting, by the UE, the data in the uplinktransmission segment in response to success of the LBT procedure.
 8. Themethod of claim 6, wherein the receiving the location includes one of:receiving a gap pattern identifying the location of the plurality of LBTgaps in the fixed frame period; or receiving identification of a set oftransmission resources in the fixed frame period, wherein the refrainingfrom transmissions includes rate matching around the set oftransmission.
 9. An apparatus configured for wireless communication, theapparatus comprising: at least one processor; and a memory coupled tothe at least one processor; wherein the at least one processor isconfigured: to determine, by a base station, a plurality of potentialtransmission bursts within a fixed frame period in a frame-basedequipment (FBE) mode network; to reserve, by the base station, aplurality of listen before talk (LBT) gaps before a starting position ofeach burst of the plurality of potential transmission bursts; tocommunicate, by the base station, a location of the plurality of LBTgaps to one or more network entities connected for communication on theFBE mode network; and to contend, by the base station, for access to thefixed frame period at a beginning of the fixed frame period.
 10. Theapparatus of claim 9, wherein the configuration of the at least oneprocessor to contend for access to the fixed frame period includesconfiguration of the at least one processor: to perform an LBTprocedure; and to transmit at least a common downlink control signal, inresponse to success of the LBT procedure, wherein the downlink controlsignal identifies to one or more served user equipments (UEs) that thefixed frame period is available for communication, wherein theconfiguration of the at least one processor to contend is performed bythe base station at every fixed frame period regardless of having datafor transmission.
 11. The apparatus of claim 9, wherein the one or morenetwork entities includes one or more of: one or more served userequipments (UEs); and one or more neighboring base stations.
 12. Theapparatus of claim 11, wherein the configuration of the at least oneprocessor to determine includes configuration of the at least oneprocessor to one of: obtain a downlink-uplink configuration for thefixed frame period from a central controller; negotiate thedownlink-uplink configuration with one or more additional base stations;or determine at least one of: uplink or downlink transmission schedulefor the fixed frame period.
 13. The apparatus of claim 9, wherein theconfiguration of the at least one processor to communicate the locationincludes configuration of the at least one processor to one of: signal agap pattern identifying the location of the plurality of gaps in thefixed frame period; or identify a set of transmission resources in thefixed frame period around which the one or more network entities are torate match around, wherein the set of transmission resources includesthe location of the plurality of gaps.
 14. An apparatus configured forwireless communication, the apparatus comprising: at least oneprocessor; and a memory coupled to the at least one processor; whereinthe at least one processor is configured: to receive, by a userequipment (UE) from a serving base station, a location of a plurality ofLBT gaps within a fixed frame period on a frame-based equipment (FBE)mode network; to refrain, by the UE, from transmissions during thelocation of the plurality of LBT gaps; and to detect, by the UE, acommon control signal from the serving base station at a beginning ofthe fixed frame period, wherein the common control signal identifies thefixed frame period is available for transmission according to anuplink-downlink configuration.
 15. The apparatus of claim 14, furtherincluding configuration of the at least one processor: to identify, bythe UE, data for uplink transmission; to perform, by the UE, a listenbefore talk (LBT) procedure at a gap of the plurality of LBT gapsassociated with an uplink transmission segment of the uplink-downlinkconfiguration; and to transmit, by the UE, the data in the uplinktransmission segment in response to success of the LBT procedure. 16.The apparatus of claim 14, wherein the configuration of the at least oneprocessor to receive the location includes configuration of the at leastone processor to one of: receive a gap pattern identifying the locationof the plurality of LBT gaps in the fixed frame period; or receiveidentification of a set of transmission resources in the fixed frameperiod, wherein the configuration of the at least one processor torefrain from transmissions includes rate matching around the set oftransmission.